What it means
Dilution happens because raising money by selling equity means creating new shares. If a founding team owns 8,000,000 shares out of 8,000,000 in issue, they own 100%; if the company then issues 2,000,000 new shares to investors, the founders still hold 8,000,000 but now own 80%.
Nothing was taken from them, the denominator simply grew. The reason this matters beyond ego is control and incentive.
Ownership percentage drives voting power, board composition and the founders' share of any eventual sale, and once a team drops well below a meaningful stake, investors may worry that the people running the business no longer have enough at risk to keep pushing. A founding team diluted to single digits before a major exit is a recognised warning sign in venture investing.
The way to assess it is simple arithmetic on the capitalisation table: track founder shares against total shares outstanding on a fully diluted basis, which includes options, warrants and convertible instruments as though they had already converted. Founders often forget the option pool, which is usually created or topped up before a round and comes disproportionately out of existing holders.
The pool is dilution just as much as the investor's stake is. The most useful reframing is that the goal is not to minimise dilution but to maximise the value of what remains.
Giving up 20% for capital that triples enterprise value leaves founders better off in dollars, whereas refusing to dilute and running out of cash leaves them with a large share of nothing. Founders who negotiate hard on valuation and pool size, then accept the dilution, generally end up ahead of those who resist raising at all.
Common defences include raising less, using convertible instruments carefully, negotiating a smaller option pool or one created after the round, and hitting milestones so later rounds are priced higher. Each helps at the margin, but the biggest determinant is how much the business is worth when it raises.
In practice
Real-world examples.
Example
Two co-founders of a logistics startup own 50% each after incorporation. Following a seed round, a Series A and two option pool increases, they hold 26% and 26%, and they agree a vesting refresh for themselves so their remaining incentive is tied to the next five years.
Example
A hardware founder raises three bridge rounds on convertible notes to avoid setting a valuation. When the notes convert at a discount alongside the priced round, her stake falls from 41% to 22% in a single step, far more than she had modelled.
Example
A software team negotiates the option pool to be created after the investment rather than before, shifting part of the pool dilution to the incoming investor and preserving roughly four percentage points of founder ownership.
Formula
Calculation
Founder ownership after a round = Founder shares / Total shares outstanding after the issue.
A founding team starts with 8,000,000 shares, being 100% of the company.
Seed round: 2,000,000 new shares issued to investors. Total shares = 8,000,000 + 2,000,000 = 10,000,000. Founder ownership = 8,000,000 / 10,000,000 = 80%.
Series A: 2,500,000 new shares issued. Total shares = 10,000,000 + 2,500,000 = 12,500,000. Founder ownership = 8,000,000 / 12,500,000 = 64%.
Option pool top-up: 1,500,000 shares reserved. Fully diluted total = 12,500,000 + 1,500,000 = 14,000,000. Founder ownership = 8,000,000 / 14,000,000 = 57.1%.
The founders have gone from 100% to 57.1% while their share count never changed. If the company is now worth $70,000,000, their combined stake is worth 8,000,000 / 14,000,000 x $70,000,000 = $40,000,000, against a 100% stake in a business that was worth almost nothing at the start. The percentage fell and the value rose, which is the whole point of the trade.Case study
Seen in the real world.
Kestrel Analytics is an illustrative, fictional data business founded by three engineers who each held one third of 9,000,000 shares. Over four years they raised a seed round, a Series A and a Series B, and the board twice expanded the employee option pool to hire senior staff.
By the Series B close the fully diluted share count was 30,000,000, leaving the founders with 9,000,000 shares between them, or 30% of the company, down from 100%. One founder objected loudly, arguing they had been treated unfairly. The chief financial officer showed the other calculation: at the Series B price the company was valued at $180,000,000, so the founders' collective stake was worth $54,000,000, against a business that had been worth nothing but an idea at the outset.
The genuine issue was different. With 30% split three ways, no founder held enough to influence a sale on their own, and the board had shifted to investor control two rounds earlier. The illustrative lesson is that dilution is best judged in two currencies at once, dollars and control, and founders tend to watch only the first.
Watch out
Common mistakes.
- Believing dilution reduces the number of shares a founder owns, when it is the total share count that grows.
- Ignoring the option pool when modelling a round, which typically costs existing shareholders several percentage points of ownership.
- Refusing all dilution to protect a percentage, and starving the business of the capital that would have made the remaining stake valuable.
Questions
People also ask.
How much dilution is normal per funding round?
Commonly around 15% to 25% for a priced round, though the range varies widely by stage, sector and market conditions.
Do founders lose control as soon as they fall below 50%?
Not automatically; control depends on board seats, voting rights and protective provisions, which can shift before the ownership does.
Can founders reverse dilution?
Not directly, though they can be issued new equity through refresh grants, secondary purchases or performance-based awards approved by the board.
From the founder's library
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